Bugfix: failover via API didn't work due to change in _MemberStatus

Originally fetch_nodes_statuses was returning a tuple, later it was
wrapped into namedtuple _MemberStatus and recently _MemberStatus was
extened with watchdog_failed field, but api.py was still relying on
usual tuple and checking failover limitations on it's own instead of
calling `failover_limitation` method.

patroni/api.py

@@ -300,8 +300,8 @@ def is_failover_possible(self, cluster, leader, candidate):
             members = [m for m in cluster.members if m.name != cluster.leader.name and m.api_url]
             if not members:
                 return 'failover is not possible: cluster does not have members except leader'
-        for _, reachable, _, _, tags in self.server.patroni.ha.fetch_nodes_statuses(members):
-            if reachable and not tags.get('nofailover', False):
+        for st in self.server.patroni.ha.fetch_nodes_statuses(members):
+            if st.failover_limitation() is None:
                 return None
         return 'failover is not possible: no good candidates have been found'
 

patroni/ha.py

@@ -26,6 +26,7 @@ class _MemberStatus(namedtuple('_MemberStatus', 'member,reachable,in_recovery,wa
         in_recovery - `!True` if pg_is_in_recovery() == true
         wal_position - value of `replayed_location` or `location` from JSON, dependin on its role.
         tags - dictionary with values of different tags (i.e. nofailover)
+        watchdog_failed - indicates that watchdog is required by configuration but not available or failed
     """
     @classmethod
     def from_api_response(cls, member, json):

patroni/version.py

@@ -1 +1 @@
-__version__ = '1.3'
+__version__ = '1.3.1'

tests/test_api.py

@@ -6,6 +6,7 @@
 from mock import Mock, patch
 from patroni.api import RestApiHandler, RestApiServer
 from patroni.dcs import ClusterConfig, Member
+from patroni.ha import _MemberStatus
 from patroni.utils import tzutc
 from six import BytesIO as IO
 from six.moves import BaseHTTPServer
@@ -38,7 +39,7 @@ def postmaster_start_time():
 
 
 class MockWatchdog(object):
-    is_healthy = True
+    is_healthy = False
 
 
 class MockHa(object):
@@ -64,7 +65,7 @@ def delete_future_restart():
 
     @staticmethod
     def fetch_nodes_statuses(members):
-        return [[None, True, None, None, {}]]
+        return [_MemberStatus(None, True, None, None, {}, False)]
 
     @staticmethod
     def schedule_future_restart(data):